title: Effects of PTHrP on chondrocytes of sika deer antler.
abstract: Parathyroid-hormone-related peptide (PTHrP) is an important regulator of chondrocyte differentiation in growth plates but little is known about its role in deer antler cartilage. The aim of the present study was to use the deer antler as a model to determine the possible role of PTHrP in regulating chondrocyte differentiation of deer antler. PTHrP and its receptor PTH1R mRNA were highly expressed in the perichondrium and cartilage of sika deer antler, as shown by in situ hybridization. Chondrocytes of deer antler were identified by toluidine blue staining of glycosaminoglycan and immunocytochemical staining of type II collagen (Col II). Treatment with PTHrP (1-34) reduced the expression of prehypertrophic chondrocyte marker Col IX and hypertrophic chondrocyte marker Col X. In order to confirm the mechanism of action of PTHrP, we initially examined the expression of cyclin D1, Bcl-2 and runt-related transcription factor 2 (Runx2) in sika deer antler by in situ hybridization and found that cyclin D1, Runx2 and Bcl-2 mRNA were also expressed in antler chondrocytes. Exogenous PTHrP induced the expression of cyclin D1 and Bcl-2 mRNA by various signalling pathways, whereas it inhibited Runx2 expression through PKA, p38MAPK, MEK and PI3K signalling pathways. Thus, PTHrP might promote the proliferation of antler chondrocytes and prevent their differentiation; it might furthermore influence the growth and development of sika deer antler.
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Guo
authors.forename: Shou-Tang
authors.initials: ST
authors.lastname: Wang
authors.forename: Cui-Cui
authors.initials: CC
authors.lastname: Duan
authors.forename: Dang-Dang
authors.initials: DD
authors.lastname: Li
authors.forename: Xue-Chao
authors.initials: XC
authors.lastname: Tian
authors.forename: Qu-Yuan
authors.initials: QY
authors.lastname: Wang
authors.forename: Zhan-Peng
authors.initials: ZP
authors.lastname: Yue
mesh_terms: D000818:Animals; D000999:Antlers / Q000166:cytology* / Q000502:physiology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D019938:Cyclin D1 / Q000235:genetics; D003670:Deer / Q000502:physiology*; D005786:Gene Expression Regulation; D044162:Parathyroid Hormone-Related Protein / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000235:genetics
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D044162:Parathyroid Hormone-Related Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D044168:Receptor, Parathyroid Hormone, Type 1; D019938:Cyclin D1